Main Energy Controller
The Main Energy Controller is a room in Metroid Prime 2: Echoes. It is in the Great Temple on Aether. The room is much larger than the other Energy Controller housings. It hold the primary Energy Controller for the Luminoth's energy system. The energy from the 3 regional Energy Controllers in the Agon, Torvus, and Sanctuary sectors have their energy directed into the Main Energy Controller, which links up and activates the Light-Based Teleportation System once they're all reactivated. It also contains U-Mos, the fifth and current Sentinel of Aether.
Along the outside, there are several support beams that also contain energy housings, several of which are seen all over the Temple Grounds. Before leaving, Samus can scan the Luminoth Lore Projector, which explains the Luminoth's origins.
When Samus Aran first arrives and approaches the Energy Controller, she encounters U-Mos, who relates the events leading up to Aether's division and war with the Ing. He tells Samus the Energy Transfer Module is bonded to her suit, and that only she has the power to restore the Light of Aether harbored in Dark Aether to the proper temples. Before she departs on her quest, U-Mos updates her Translator Module so she can interpret Violet Holograms.
Each time Samus restores the Light of Aether to one of the regional Energy Controllers, she must venture back to the Main Energy Controller to speak to U-Mos. If she tries to move on to the next area of the Great Temple to proceed further into Aether, a mental shield created by U-Mos will bar her way and will only be deactivated after they converse.
After Samus restores all the temples, U-Mos tells Samus that Dark Aether is still being supported by one final energy controller and it's guarded by the Emperor Ing. He uses the Light of Aether from the three temples to trifurcate the Energy Controller, revealing the Light Suit.